Signal-transmitter-testing device.



C. L. GOODRUM.

SIGNAL TRANSMITTER TESTING DEVICE.

APPLICATION FILED JUNE 23. 1915.

1 1 96 85 5 Patented Sept. 5, 1916.

Wi/aessea: lnvenloh 9 I C/mr/es L. Goad/um.

s ATENT @FETE,

CHARLES L. GOODRUM, OF NEW YORK, N. Y., AS SIGNOR, BY MESNE ASSIGNMENTii, T0

WESTERN ELECTRIC CGMPANY,

INCORPORATED, ACGRPORATION 0F 'NIEW YORK SIGNAL-TRANSMITTER-TESTING DEVICE.

To all whom it may concern 1. I Be it known that I, CHARLES LANE G RUM, a citizen of the United States, resid-' in the countyof New, New York, have inventing at New York, York and State of ed certain new and useful Improvements in Signal-Transmitter-Testing -Devices, of which the following is a full,'clear, concise, and exact description.

This invention relates to the testing of signal transmitters used in connection with the roller 18 is another impression roller 25 automatic telephone or other electric systems. Its general object isto provide a new and improved testing, device which will fur nish arrangement of current impulses produced by a signal transmittenand will enable a comparison to be made between the current impulses from the signal transmitter to be tested and current impulsessuch as would be sent out by. a properly adjusted or stand-' ard signal transmitter; In the drawing, agrammatic view of a testlng device embodying my invention and the circuitsand apparatus through which the signal transmitter to be tested is connected to said test-' ing device; and Fig. 2 is a fragmentary plan window of the testing d e'-. vice through which the tape "bearing the v ew showing the graphic indications is visible.

In the drawing, the tes ting'device is shown as a printing mechanism which prints on a,

moving tape indications corresponding in length and arrangement with a standardset shown in thedrawing as wired, through certain intermediary apparatus, to a subscribof current impulses and also prints indications representing a. set of current impulses sent out by the signal transmitter-to'bet est' This printing mechanism comprises a a plurality of lugs 17 with which an impres- Specification of Letters Patent.

a graphic indication of the length and Figure 1 is a .partlyvdi-" position as shown.

cations corresponding -rangementto the current impulses produced by the signal transmitter to be tested. For

f passbeneath a window I of sion "roller 18 cooperates.

indications whichthey print on tape 10 correspond to standardcurrent impulses from a properly adjusted signal transmitter. .The impression roller 18 is shown supported in the' end of an L-shaped' armature 20 pivot- Patented Sept. 5, was. Application marine aaie ai fs i inaasgsa. i v

l I i 7 These lugs 17are ofsuch a shape" and arrangement'thatthe' ally mounted at 21in theframe of an elec- 'tromagne't 22; anda spring 23 serves to retract the. armatureto the position" shown. Located beneath the tape 10 and adjacent which serves to force the tape 10 and printing ribbon 9 into engagement with the smooth cylindrical'ssurface of the printing drum 5. l/Vhile this impression roller 25 is in engagement with the-tape, a graphic indication in the form'of a'line is printed on the top of said tape;- The impression roller 25 is mounted in the 1 end of an L-shaped armature 26 pivotally mounted at 27 on the frame of electromagnet 28; and a spring 29 serves; to hold said armature in its retracted It is the impression the printing of indiin length and arroller 25 which causes convenience of observation, the tape 10'may glass mounted on a frame 30 as shown; and said frame 130 may form a cutting edge against which sections of tape may be torn o The testing device above described is 'ers station of an automatic telephone systhe right end of tem. The apparatus at the subscribers station is'indicated by well-known conventional symbols among which is that which represents the signal transmitter 31, which when operated serves to produce current impulses 'by interruptions and completions of the circuit. The circuits and apparatus located between the subscribers station and the testing device are similar to the arrangement shown, described and claimed in my copending application for patent Serial No.

14,971, filed March 17 1915. The arrangement will be readily understood from the following description of the mode of operation of the testing device shown.

It is of course understood that the testing device may be-located at any suitable place, preferably in the central otiice of an automatic telephone exchange, and that the signal transmitter to be tested may be connected to it in any suitable manner. As shown, the line wires leading to the substation apparatus, including the signal trans mitter 31, lead to a used to connect the testing apparatus to the circuit on which the signal transmitter to be tested is located. Assuming that the switch 32 is operated so as to connect the substation circuit to the testing apparatus, and assuming that the receiver at the sub station has been removed from the switchhook, the line relay 34 will be energized through the following circuit: from grounded battery 35 through one winding of the relay 34, one set of contacts of the key 32, one

of the line wires to the substation, the substation apparatus, contacts of key of the relay 34 to ground. The energization of the line relay 34 causes said relay to close a circuit for a slow-acting relay 36 as followsi from grounded battery 37, coil of relay 36, and front contacts of line relay 34 to ground. Until the signal transmitter 31 at the substation is actuated, no further change in the circuits and apparatus takes place. l/Vhen the signal transmitter 31 is operated, the first impulse produced by the opening of the line circuit deenergizes the line relay' 34 causing its armature to open its front contacts and close its back contacts. The closing of the back contacts of the relay 34 completesa circuit for a slow-acting relay 38 as follows: from grounded battery.

39, coil of relay 38, contacts of slow-acting relay 36 (which have not opened), and back contacts of line relay 34 to ground. The energization of relay 38 closes both of its sets of contacts. The closing of the lefthand set of contacts of relay 38 completes a circuit for the electromagnet 22 controlling the printing of indications corresponding to standard impulses, from grounded battery 40, =which circuit is maintained throughout the time that impulses are being sent from the signal transmitter, owing to the fact that the intervals of no current through the coils of slow-acting relays 36 and 38 are too short to allow the deenergization of said relays. The closing of the right-hand contacts of relay 38 completes a circuit for the electromagnet 28, which controls the printing of impulses sent by the signal. transmitter to be tested, as follows: from grounded battery through electrokey 32 which may be the other line wire, the other 32, and the other winding magnet 28, right-hand contacts of relay 38,

contacts of relay 36, and back contacts of P the line relay 34 is reenergized, with the consequent opening of its back contacts and closing of its front contacts. This has no efi'ect on the electromagnet 22 which is maintained energized as before explained, but the circuit for the electromagnet' 28 is interrupted at the back contacts of the relay 34, and the impression roller 25 is moved out of contact with the tape. Upon the sending of the next current impulse by the signal transmitter, theelectromagnet 28 is renergized in the same manner as before, and another indication corresponding to that impulse is' thereby printed on the tape. In this manner, the electromagnet "28 is repeatedly energized in unisonwith the current impulses sent by the signal transmitter, and the indications printed on the tape by the impression ji oller 25 controlled by said magnet correspond in number, length and arrangement with the impulses sent. .ifter the last impulse has been sent and the line circuit has been completedfor a sufficient interval of time, the energization ofthe re lay 34 and the consequent openinglofits back contacts, will open the circuit for the relay 38 and will cause the latter to open both of its sets of contacts which are located in the circuits of the electromagnets 22 and 28. The printing of indications corresponding to standard impulses is, therefore, stopped after the impulses have all been sent from the signal transmitter to be tested. The tape is then ready to be observed either through the window in the frame 30 or after the tape has been pulled out and torn ofi.

What is claimed is:

1. A signal transmitter testing device comprising a tape, means for moving the same, means for making indications on said tape corresponding in length and arrangement to standard current impulses from a ing means for printing indications on said lit'l tape corresponding'in length and arrangement to standard .ourrent impulses from a signal transmitter, another electromagnetically controlled printing means for printing other indications on said tape corresponding inlength and arrangement to the .current impulses of the signal transmitter CHARLES L. GOODRUM. 

